The present invention relates to an optical projection device.
Optical projection devices having an optical mask that is shone through by the light path, for example a slide, have long been known. In the simplest form of an optical projection device, a point light source is used, starting from which a diverging beam of rays passes through the optical mask and impinges on a projection screen. Since with such a simple optical projection device, only a small part of the radiation emerging from the point light source can be utilized, in traditional projection devices the partly transmissive mask is illuminated as uniformly as possible by means of an illumination arrangement with maximum possible exploitation of the light source radiation, while an optical imaging arrangement serves for as precise as possible an imaging of the planar object geometry of the mask onto the reflective or transmissive projected area. In such a conventional projection system the luminous efficacy is typically also relatively low since a considerable portion of the light is lost due to diffusion. In addition, the expenditures for materials and design for such a system are very high.